Structural and Functional Brain Changes at Early and Late Stages of Complex Regional Pain Syndrome

• Published in: The journal of pain Vol. 19; no. 2; pp. 146 - 157
• Main Authors: Shokouhi, Mahsa, Clarke, Collin, Morley-Forster, Patricia, Moulin, Dwight E., Davis, Karen D., St. Lawrence, Keith
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2018
• Subjects: arterial spin labeling; cerebral blood flow; Complex regional pain syndrome; sensorimotor connectivity; voxel-based morphometry; sensorimotor connectivity; cerebral blood flow; voxel-based morphometry; Complex regional pain syndrome; arterial spin labeling
• ISSN: 1526-5900; 1528-8447
• DOI: 10.1016/j.jpain.2017.09.007

•We studied brain changes at early vs late stages of complex regional pain syndrome.•Early gray matter volume decrease was found in sensorimotor and parietal cortices.•At early stage, cerebral perfusion was reduced in parts of the limbic system.•We found higher perfusion in motor cortex but no gray matter changes at late stage.•Sensorimotor network changes at both stages showed impairment of motor control. Brain plasticity is demonstrated in complex regional pain syndrome (CRPS), although it is unclear how it modulates at different stages of CRPS. The observation that symptoms can progress over time suggests that the pattern of brain changes might also evolve. We measured structural and functional changes as well as sensorimotor integration at the early stage (ES) and late stage (LS) of CRPS. Twelve ES patients, 16 LS patients, and 16 age- and sex-matched controls were recruited. Gray matter (GM) volume was estimated using voxel-based morphometry. Cerebral perfusion was measured using arterial spin labeling, because it provides a measure of resting neural activity. Connectivity to sensorimotor regions was evaluated using blood-oxygen level-dependent images. The ES group showed reduced GM volume and perfusion in areas associated with spatial body perception, somatosensory cortex, and the limbic system, whereas the LS group exhibited increased perfusion in the motor cortex but no changes in GM volume. However, in the LS group, GM volume in areas associated with pain processing was negatively correlated with average pain levels, likely reflecting a response to ongoing pain. Furthermore, connectivity to sensorimotor cortex showed disruptions in regions associated with motor control and planning, implying impairment of higher-order motor control. This article presents brain changes at ES and LS of CRPS. We found different patterns of brain changes between these 2 stages. Understanding modulation of brain plasticity at different stages of CRPS could help understand the diversity in outcomes and treatment response and hopefully improve treatment planning.